A cutting tool having a tip to which a high hardness material is joined by brazing, as typified by a cBN (cubic boron nitride) or diamond cutting tool, has been conventionally manufactured and used for cutting processing of special steel and any other various materials.
Specifically, a tool formed by joining cBN and cemented carbide by brazing has been manufactured and sold, for example (e.g., Non-Patent Document 1). Alternatively, a joined product formed by joining PCD (sintered diamond) or cBN and ceramics or cermet by brazing has been proposed (e.g., Patent Documents 1 and 2). In addition, a cutting tool formed by joining cemented carbide or cermet and high-speed steel or the like by brazing with a Cu brazing filler has also been proposed (e.g., Patent Document 3).    Patent Document 1: Japanese Patent Laying-Open No. 2002-36008    Patent Document 2: Japanese Patent Laying-Open No. 11-320218    Patent Document 3: Japanese Patent Laying-Open No. 11-294058    Non-Patent Document 1: IGETALLOY Cutting Tool ('07-'08 General Catalogue) issued by Sumitomo Electric Hardmetal Co., October, 2006, p. L4, Coated SUMIBORON Series